While so many refuse to focus on anything but the Bears offense and hope that the arrival of coach Marc Trestman finally will propel that unit into the 21st century, and most of the rest of Bear Nation preaches that defense always has been the Bear way and always will be, it very well could be the Bears’ special teams that are the difference between contending for a playoff spot again this season or taking a step backward.

It is easy to understand how folks might overlook the Bears’ special teams. One could make the argument former Bear Dave Toub was the best special teams coach in the NFL over the past eight or nine years. He’s now moved on to Kansas City.

Devin Hester was thought to be fast-tracking to Canton as the greatest kick returner in the history of the game until Jerry Angelo and Lovie Smith made up their minds he would be a receiver at all costs, including seriously diminishing his effectiveness in the return game.

Robbie Gould, the fourth most accurate kicker in the history of the NFL, was lost for the season with four games remaining last year and needed surgery on a damaged hamstring, potentially a death sentence to the careers of some placekickers.

And this Bears club is so thin at some positions fans might wonder if it even can fill out its coverage and return teams. It’s no wonder the specialty units have been virtually ignored thus far in the preseason.

But they’re not being ignored by Trestman, who made one of his main focuses for preseason Game 2 getting more production out of his teams.

“We really did want to get a return or two out of Devin because you saw again on the opening kick what an incredible weapon he can be,” Trestman said. “We’re really excited about the year Devin could have.”

Hester is more than Mr. Excitement and a momentum and game-changer. During the Bears’ 2006 Super Bowl season, and again when they won the NFC North in 2011, the Bears led the NFL in average starting field position beccause of all of their special teams work, but in particular because of Hester’s unique return ability.

This could be particularly important this season, if Hester can bounce back because of the time it might take for both the offense and defense to settle into new schemes and new coaching.

New special teams coach Joe DeCamillas couldn’t be happier to have Hester saying “Devin’s attitude’s been great, he’s been great ever since I got here and we all know what he can do.”

DeCamillas also feels fortunate to have a healthy Gould back.

“He knows an awful lot about the kicking game, he’s a real piece of work,” he said.

DeCamillas is a piece of work as well, having served as the special teams coach with six different NFL teams (Denver, Giants, Atlanta, Jacksonville and Dallas) continuously since 1988. He also carries the title of assistant head coach and there is little concern among NFL insiders that he can pick up where Toub left off.

The one big issue he faces is the roster decisions that will be made to fill out his teams.

“We have a core of veterans who will make changes on special teams difficult. We’ve got a great group.”

Perhaps they do, but . . .

While that group almost certainly will be led by Eric Weems, Blake Costanzo, Zack Bowman and Sherrick McManis, the rest of DeCamillas’ coverage teams will be dictated by roster battles at positions where few clear choices have emerged.

Until decisions have been made on the second and third tight ends, whether the roster can afford a seventh linebacker, if there is a young receiver or running back who can contribute and who the backup safeties and cornerbacks are, the coverage units will have to wait.

• Hub Arkush covers the Bears for Shaw Media and HubArkush.com. Write to him at harkush@shawmedia.com.